Angiotensin II, Hypercholesterolemia, and Vascular Smooth Muscle Cells: A Perfect Trio for Vascular Pathology

Deciphering deep-sea chemosynthetic symbiosis by single-nucleus RNA-sequencing

Bathymodioline mussels dominate deep-sea methane seep and hydrothermal vent habitats and obtain nutrients and energy primarily through chemosynthetic endosymbiotic bacteria in the bacteriocytes of their gill. However, the molecular mechanisms that orchestrate mussel host-symbiont interactions remain unclear. Here, we constructed a comprehensive cell atlas of the gill in the mussel Gigantidas platifrons from the South China Sea methane seeps (1100 m depth) using single-nucleus RNA-sequencing (snRNA-seq) and whole-mount in situ hybridisation. We identified 13 types of cells, including three previously unknown ones, and uncovered unknown tissue heterogeneity. Every cell type has a designated function in supporting the gill's structure and function, creating an optimal environment for chemosynthesis, and effectively acquiring nutrients from the endosymbiotic bacteria. Analysis of snRNA-seq of in situ transplanted mussels clearly showed the shifts in cell state in response to environmental oscillations. Our findings provide insight into the principles of host-symbiont interaction and the bivalves' environmental adaption mechanisms.

Angiotensin II constricts mouse iliac arteries: possible mechanism for aortic aneurysms

Abdominal aortic aneurysms (AAA) result from maladaptive remodeling of the vascular wall and reduces structural integrity. Angiotensin II (AngII) infusion has become a standard laboratory model for studying AAA initiation and progression. We determined the different vasoactive responses of various mouse arteries to Ang II. Ex vivo isometric tension analysis was conducted on 18-week-old male C57BL/6 mice (n = 4) brachiocephalic arteries (BC), iliac arteries (IL), and abdominal (AA) and thoracic aorta (TA). Arterial rings were mounted between organ hooks, gently stretched and an AngII dose response was performed. Rings were placed in 4% paraformaldehyde for immunohistochemistry analysis to quantify peptide expression of angiotensin type 1 (AT1R) and 2 receptors (AT2R) in the endothelium, media, and adventitia. Results from this study demonstrated vasoconstriction responses in IL were significantly higher at all AngII doses when compared to BC, and TA and AA responses (maximum constriction-IL: 68.64 ± 5.47% vs. BC: 1.96 ± 1.00%; TA: 3.13 ± 0.16% and AA: 2.75 ± 1.77%, p < 0.0001). Expression of AT1R was highest in the endothelium of IL (p < 0.05) and in the media and (p < 0.05) adventitia (p < 0.05) of AA. In contrast, AT2R expression was highest in endothelium (p < 0.05), media (p < 0.01, p < 0.05) and adventitia of TA. These results suggest that mouse arteries display different vasoactive responses to AngII, and the exaggerated response in IL arteries may play a role during AAA development.

ER stress mediates Angiotensin II-augmented innate immunity memory and facilitates distinct susceptibilities of thoracic from abdominal aorta to aneurysm development

To determine the roles of endoplasmic reticulum (ER) stress and trained immunity, we performed transcriptome analyses on the thoracic aorta (TA) and abdominal aorta (AA) from the angiotensin II (Ang II)-HFD-ApoE-KO aneurysm model and made significant findings: 1) Ang II bypassed HFD-induced metabolic reprogramming and induced stronger inflammation in AA than in TA; 2) Ang II and HFD upregulated 890 genes in AA versus TA and induced cytokine signaling; 3) Ang II AA and TA upregulated 73 and 68 cytokines, scRNA-Seq identified markers of macrophages and immune cells, cell death regulators, respectively; transdifferentiation markers of neuron, glial, and squamous epithelial cells were upregulated by Ang II-AA and TA; and pyroptosis signaling with IL-1β and caspase-4 were more upregulated in Ang II-AA than in TA; 4) Six upregulated transcriptomes in patients with AAA, Ang II AA, Ang II TA, additional aneurysm models, PPE-AAA and BAPN-Ang II-AAA, were partially overlapped with 10 lists of new ER stress gene sets including 3 interaction protein lists of ER stress regulators ATF6, PERK, and IRE1, HPA ER localization genes, KEGG signal genes, XBP1 transcription targets, ATF4 (PERK) targets, ATF6 targets, thapsigargin ER stress genes, tunicamycin-ER stress genes, respectively; 5) Ang II-AA and TA upregulated ROS regulators, MitoCarta genes, trained immunity genes, and glycolysis genes; and 6) Gene KO transcriptomes indicated that ATF6 and PERK played more significant roles than IRE1 in promoting AAA and trained immunity whereas antioxidant NRF2 inhibited them. Our unprecedented ER-focused transcriptomic analyses have provided novel insights on the roles of ER as an immune organelle in sensing various DAMPs and initiating ER stress that triggers Ang II-accelerated trained immunity and differs susceptibilities of thoracic and abdominal aortas to diseases.

Current understanding of the contribution of lactate to the cardiovascular system and its therapeutic relevance

Research during the past decades has yielded numerous insights into the presence and function of lactate in the body. Lactate is primarily produced via glycolysis and plays special roles in the regulation of tissues and organs, particularly in the cardiovascular system. In addition to being a net consumer of lactate, the heart is also the organ in the body with the greatest lactate consumption. Furthermore, lactate maintains cardiovascular homeostasis through energy supply and signal regulation under physiological conditions. Lactate also affects the occurrence, development, and prognosis of various cardiovascular diseases. We will highlight how lactate regulates the cardiovascular system under physiological and pathological conditions based on evidence from recent studies. We aim to provide a better understanding of the relationship between lactate and cardiovascular health and provide new ideas for preventing and treating cardiovascular diseases. Additionally, we will summarize current developments in treatments targeting lactate metabolism, transport, and signaling, including their role in cardiovascular diseases.

Limonin ameliorates cardiovascular dysfunction and remodeling in hypertensive rats

AIMS

Limonin is a tetracyclic triterpenoid isolated from citrus fruits. Here, the effects of limonin on cardiovascular abnormalities in nitric oxide-deficient rats induced by N^ω-Nitrol-arginine methyl ester (L-NAME) were explored.

MAIN METHODS

Male Sprague Dawley rats were given L-NAME (40 mg/kg, drinking water) for 3 weeks and then treated daily with polyethylene glycol (vehicle), limonin (50 or 100 mg/kg) or telmisartan (10 mg/kg) for two weeks.

KEY FINDINGS

Limonin (100 mg/kg) markedly reduced L-NAME-induced hypertension, cardiovascular dysfunction and remodeling in rats (P < 0.05). Increases in systemic angiotensin-converting enzyme (ACE) activity and angiotensin II (Ang II) and a reduction in circulating ACE2 were restored in hypertensive rats treated with limonin (P < 0.05). Reductions in antioxidant enzymes and nitric oxide metabolites (NOx) and increases in oxidative stress components induced by L-NAME were relieved by limonin treatment (P < 0.05). Limonin suppressed the increased expression of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 in cardiac tissue and circulating TNF-α in rats that received L-NAME (P < 0.05). Changes in Ang II receptor type I (AT1R), Mas receptor (MasR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) and NADPH oxidase subunit 2 (gp91^phox) protein expression in cardiac and aortic tissue were normalized by limonin (P < 0.05).

SIGNIFICANCE

In conclusion, limonin ameliorated L-NAME-induced hypertension, cardiovascular dysfunction and remodeling in rats. These effects were relevant to restorations of the renin-angiotensin system, oxidative stress and inflammation in NO-deficient rats. The molecular mechanisms are associated with the modulation of AT1R, MasR, NF-ĸB and gp91^phox protein expression in cardiac and aortic tissue.

Role of Angiotensin II in Cardiovascular Diseases: Introducing Bisartans as a Novel Therapy for Coronavirus 2019

Cardiovascular diseases (CVDs) are the main contributors to global morbidity and mortality. Major pathogenic phenotypes of CVDs include the development of endothelial dysfunction, oxidative stress, and hyper-inflammatory responses. These phenotypes have been found to overlap with the pathophysiological complications of coronavirus disease 2019 (COVID-19). CVDs have been identified as major risk factors for severe and fatal COVID-19 states. The renin-angiotensin system (RAS) is an important regulatory system in cardiovascular homeostasis. However, its dysregulation is observed in CVDs, where upregulation of angiotensin type 1 receptor (AT1R) signaling via angiotensin II (AngII) leads to the AngII-dependent pathogenic development of CVDs. Additionally, the interaction between the spike protein of severe acute respiratory syndrome coronavirus 2 with angiotensin-converting enzyme 2 leads to the downregulation of the latter, resulting in the dysregulation of the RAS. This dysregulation favors AngII/AT1R toxic signaling pathways, providing a mechanical link between cardiovascular pathology and COVID-19. Therefore, inhibiting AngII/AT1R signaling through angiotensin receptor blockers (ARBs) has been indicated as a promising therapeutic approach to the treatment of COVID-19. Herein, we review the role of AngII in CVDs and its upregulation in COVID-19. We also provide a future direction for the potential implication of a novel class of ARBs called bisartans, which are speculated to contain multifunctional targeting towards COVID-19.

Aortic Stress Activates an Adaptive Program in Thoracic Aortic Smooth Muscle Cells That Maintains Aortic Strength and Protects Against Aneurysm and Dissection in Mice

BACKGROUND

When aortic cells are under stress, such as increased hemodynamic pressure, they adapt to the environment by modifying their functions, allowing the aorta to maintain its strength. To understand the regulation of this adaptive response, we examined transcriptomic and epigenomic programs in aortic smooth muscle cells (SMCs) during the adaptive response to AngII (angiotensin II) infusion and determined its importance in protecting against aortic aneurysm and dissection (AAD).

METHODS

We performed single-cell RNA sequencing and single-cell sequencing assay for transposase-accessible chromatin (scATAC-seq) analyses in a mouse model of sporadic AAD induced by AngII infusion. We also examined the direct effects of YAP (yes-associated protein) on the SMC adaptive response in vitro. The role of YAP in AAD development was further evaluated in AngII-infused mice with SMC-specific Yap deletion.

RESULTS

In wild-type mice, AngII infusion increased medial thickness in the thoracic aorta. Single-cell RNA sequencing analysis revealed an adaptive response in thoracic SMCs characterized by upregulated genes with roles in wound healing, elastin and collagen production, proliferation, migration, cytoskeleton organization, cell-matrix focal adhesion, and PI3K-PKB/Akt (phosphoinositide-3-kinase-protein kinase B/Akt) and TGF-β (transforming growth factor beta) signaling. ScATAC-seq analysis showed increased chromatin accessibility at regulatory regions of adaptive genes and revealed the mechanical sensor YAP/transcriptional enhanced associate domains as a top candidate transcription complex driving the expression of these genes (eg, Lox, Col5a2, Tgfb2). In cultured human aortic SMCs, cyclic stretch activated YAP, which directly bound to adaptive gene regulatory regions (eg, Lox) and increased their transcript abundance. SMC-specific Yap deletion in mice compromised this adaptive response in SMCs, leading to an increased AAD incidence.

CONCLUSIONS

Aortic stress triggers the systemic epigenetic induction of an adaptive response (eg, wound healing, proliferation, matrix organization) in thoracic aortic SMCs that depends on functional biomechanical signal transduction (eg, YAP signaling). Our study highlights the importance of the adaptive response in maintaining aortic homeostasis and preventing AAD in mice.

Apitherapy combination improvement of blood pressure, cardiovascular protection, and antioxidant and anti-inflammatory responses in dexamethasone model hypertensive rats

Hypertension-induced ventricular and vascular remodeling causes myocardial infarction, heart failure, and sudden death. Most available pharmaceutical products used to treat hypertension lead to adverse effects on human health. Limited data is available on apitherapy (bee products) combinations for treatment of hypertension. This study aims to evaluate the antihypertensive effects of combinations of natural apitherapy compounds used in the medical sector to treat a variety of diseases. Rats were assigned into six groups consisting of one control group and five hypertensive groups where hypertension (blood pressure > 140/90) was induced with dexamethasone. One of these groups was used as a hypertension model, while the remaining four hypertensive groups were treated with a propolis, royal jelly, and bee venom combination (PRV) at daily oral doses of 0.5, 1.0, and 2.0 mg/kg, and with losartan 10 mg/kg. The PRV combination at all doses decreased arterial blood pressure below the suboptimal value (p < 0.001), and PRV combination treatment improved dexamethasone-induced-ECG changes. The same treatment decreased angiotensin-II, endothelin-1, and tumor growth factor β serum levels in hypertensive rats. Additionally, PRV combination improved histopathological structure, and decreased serum levels of NF-kB and oxidative stress biomarkers. We concluded that PRV combination therapy may be used as a potential treatment for a variety of cardiovascular diseases.

Vascular smooth muscle cell dysfunction in neurodegeneration

Vascular smooth muscle cells (VSMCs) are the key moderators of cerebrovascular dynamics in response to the brain's oxygen and nutrient demands. Crucially, VSMCs may provide a sensitive biomarker for neurodegenerative pathologies where vasculature is compromised. An increasing body of research suggests that VSMCs have remarkable plasticity and their pathophysiology may play a key role in the complex process of neurodegeneration. Furthermore, extrinsic risk factors, including environmental conditions and traumatic events can impact vascular function through changes in VSMC morphology. VSMC dysfunction can be characterised at the molecular level both preclinically, and clinically ex vivo. However the identification of VSMC dysfunction in living individuals is important to understand changes in vascular function at the onset and progression of neurological disorders such as dementia, Alzheimer's disease, and Parkinson's disease. A promising technique to identify changes in the state of cerebral smooth muscle is cerebrovascular reactivity (CVR) which reflects the intrinsic dynamic response of blood vessels in the brain to vasoactive stimuli in order to modulate regional cerebral blood flow (CBF). In this work, we review the role of VSMCs in the most common neurodegenerative disorders and identify physiological systems that may contribute to VSMC dysfunction. The evidence collected here identifies VSMC dysfunction as a strong candidate for novel therapeutics to combat the development and progression of neurodegeneration, and highlights the need for more research on the role of VSMCs and cerebrovascular dynamics in healthy and diseased states.

Oviductal Glycoprotein 1 Promotes Hypertension by Inducing Vascular Remodeling Through an Interaction With MYH9

BACKGROUND

Hypertension is a common cardiovascular disease that is related to genetic and environmental factors, but its mechanisms remain unclear. DNA methylation, a classic epigenetic modification, not only regulates gene expression but is also susceptible to environmental factors, linking environmental factors to genetic modification. Therefore, globally screening differential genomic DNA methylation in patients with hypertension is important for investigating hypertension mechanisms.

METHODS

Differential genomic DNA methylation in patients with hypertension, individuals with prehypertension, and healthy control individuals was screened using Illumina 450K BeadChip and verified by pyrosequencing. Plasma OVGP1 (oviduct glycoprotein 1) levels were determined using an enzyme-linked immunosorbent assay. Ovgp1 transgenic and knockout mice were generated to analyze the function of OVGP1. The blood pressure levels of the mouse models were measured using the tail-cuff system and radiotelemetry methods. The role of OVGP1 in vascular remodeling was determined by vascular relaxation studies. Protein-protein interactions were investigated using a pull-down/mass spectrometry assay and verified with coimmunoprecipitation and pull-down assays.

RESULTS

We found a hypomethylated site at cg20823859 in the promoter region of OVGP1 and plasma OVGP1 levels were significantly increased in patients with hypertension. This finding indicates that OVGP1 is associated with hypertension. In Ovgp1 transgenic mice, OVGP1 overexpression caused an increase in blood pressure, dysfunctional vasoconstriction and vasodilation, remodeling of arterial walls, and increased vascular superoxide stress and inflammation, and these phenomena were exacerbated by angiotensin II infusion. In contrast, OVGP1 deficiency attenuated angiotensin II-induced vascular oxidase stress, inflammation, and collagen deposition. These findings indicate that OVGP1 is a prohypertensive factor that directly promotes vascular remodeling. Pull-down and coimmunoprecipitation assays showed that MYH9 (nonmuscle myosin heavy chain IIA) interacted with OVGP1, whereas inhibition of MYH9 attenuated OVGP1-induced hypertension and vascular remodeling.

CONCLUSIONS

Hypomethylation at cg20823859 in the promoter region of OVGP1 is associated with hypertension and induces upregulation of OVGP1. The interaction between OVGP1 and MYH9 contributes to vascular remodeling and dysfunction. Therefore, OVGP1 is a prohypertensive factor that promotes vascular remodeling by binding with MYH9.

Tribulus terrestris L. extract ameliorates atherosclerosis by inhibition of vascular smooth muscle cell proliferation in ApoE-/- mice and A7r5 cells via suppression of Akt/MEK/ERK signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Atherosclerosis (AS) is one of major threatens of death worldwide, and vascular smooth muscle cell (VSMC) proliferation is an important characteristic in the progression of AS. Tribulus terrestris L. is a well-known Chinese Materia Medica for treating skin pruritus, vertigo and cardiovascular diseases in traditional Chinese medicine. However, its anti-AS activity and inhibition effect on VSMC proliferation are not fully elucidated.

AIMS

We hypothesize that the furostanol saponins enriched extract (FSEE) of T. terrestris L. presents anti-AS effect by inhibition of VSMC proliferation. The molecular action mechanism underlying the anti-VSMC proliferation effect of FSEE is also investigated.

MATERIALS AND METHODS

Apolipoprotein-E deficient (ApoE^-/-) mice and rat thoracic smooth muscle cell A7r5 were employed as the in vivo and in vitro models respectively to evaluate the anti- AS and VSMC proliferation effects of FSEE. In ApoE^-/- mice, the amounts of total cholesterol, triglyceride, low density lipoprotein and high density lipoprotein in serum were measured by commercially available kits. The size of atherosclerotic plaque was observed by hematoxylin & eosin staining. The protein expressions of α-smooth muscle actin (α-SMA) and osteopontin (OPN) in the plaque were examined by immunohistochemistry. In A7r5 cells, the cell viability and proliferation were tested by MTT and Real Time Cell Analysis assays. The cell migration was evaluated by wound healing assay. Propidium iodide staining followed by flow cytometry was used to analyze the cell cycle progression. The expression of intracellular total and phosphorylated proteins including protein kinase B (Akt) and mitogen-activated protein kinases (MAPKs), such as mitogen-activated extracellular signal-regulated kinase (MEK), extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), were detected by western blotting analysis.

RESULTS

FSEE significantly reduced the area of atherosclerotic plaque in high-fat diet-fed ApoE^-/- mice. And FSEE increased the protein expression level of α-SMA and decreased the level of OPN in atherosclerotic plaque, which revealed the inhibition of VSMC phenotype switching and proliferation. In A7r5 cells, FSEE suppressed fetal bovine serum (FBS) or oxidized low density lipoprotein (oxLDL)-triggered VSMC proliferation and migration in a concentration dependent manner. FSEE protected against the elevation of cell numbers in S phase induced by FBS or oxLDL and the reduction of cell numbers in G₀/G₁ phase induced by oxLDL. Moreover, the phosphorylation of Akt and MAPKs including MEK, ERK and JNK could be facilitated by FBS or oxLDL, while co-treatment of FSEE attenuated the phosphorylation of Akt induced by oxLDL as well as the phosphorylation of MEK and ERK induced by FBS. In addition, (25R)-terrestrinin B (JL-6), which was the main ingredient of FSEE, and its potential active pharmaceutical ingredients tigogenin (Tigo) and hecogenin (Heco) also significantly attenuated FBS or oxLDL-induced VSMC proliferation in A7r5 cells.

CONCLUSION

FSEE presents potent anti- AS and VSMC proliferation activities and the underlying mechanism is likely to the suppression of Akt/MEK/ERK signaling. The active components of FSEE are JL-6 and its potential active pharmaceutical ingredients Tigo and Heco. So, FSEE and its active compounds may be potential therapeutic drug candidates for AS.

Fibrotic Signaling in Cardiac Fibroblasts and Vascular Smooth Muscle Cells: The Dual Roles of Fibrosis in HFpEF and CAD

Patients with heart failure with preserved ejection fraction (HFpEF) and atherosclerosis-driven coronary artery disease (CAD) will have ongoing fibrotic remodeling both in the myocardium and in atherosclerotic plaques. However, the functional consequences of fibrosis differ for each location. Thus, cardiac fibrosis leads to myocardial stiffening, thereby compromising cardiac function, while fibrotic remodeling stabilizes the atherosclerotic plaque, thereby reducing the risk of plaque rupture. Although there are currently no drugs targeting cardiac fibrosis, it is a field under intense investigation, and future drugs must take these considerations into account. To explore similarities and differences of fibrotic remodeling at these two locations of the heart, we review the signaling pathways that are activated in the main extracellular matrix (ECM)-producing cells, namely human cardiac fibroblasts (CFs) and vascular smooth muscle cells (VSMCs). Although these signaling pathways are highly overlapping and context-dependent, effects on ECM remodeling mainly act through two core signaling cascades: TGF-β and Angiotensin II. We complete this by summarizing the knowledge gained from clinical trials targeting these two central fibrotic pathways.

Association of ACE2 Polymorphisms and Derived Haplotypes With Obesity and Hyperlipidemia in Female Spanish Adolescents

Background

In the cardiovascular (CV) system, overactivation of the angiotensin converting enzyme (ACE) may trigger deleterious responses derived from angiotensin (Ang)-II, which can be attenuated by stimulation of ACE2 and subsequent Ang-(1-7) metabolite. However, ACE2 exhibits a high degree of genetic polymorphism that may affect its structure and stability, interfering with these cardioprotective actions. The aim of this study was to analyse the relationship of ACE2 polymorphisms with cardiovascular risk factors in children.

Methodology

Five ACE2-single nucleotide polymorphisms (SNP), rs4646188, rs2158083, rs233575, rs879922, and rs2074192, previously related to CV risk factors, were analyzed in a representative sample of 12–16-year-old children and tested for their potential association with anthropometric parameters, insulin levels and the lipid profile.

Results

Girls (N = 461) exhibited lower rates of overweight, obesity, blood pressure, and glycemia than boys (N = 412), though increased plasma lipids. The triglycerides (TG)/HDL-C ratio was, however, lower in females. Interestingly, only in girls, the occurrence of overweight/obesity was associated with the SNPs rs879922 [OR 1.67 (1.02–2.75)], rs233575 [OR 1.98 (1.21- 3.22)] and rs2158083 [OR 1.67 (1.04–2.68)]. Also, TG levels were linked to the rs879922, rs233575, and rs2158083 SNPs, and the TG/HDL-C ratio was associated with rs879922 and rs233575. Levels of TC and LDL-C were associated with rs2074192 and rs2158083. Furthermore, the established cut-off level for TG ≥ 90 mg/dL was related to rs879922 [OR 1.78 (1.06–2.96)], rs2158083 [OR 1.75 (1.08–2.82)], and rs233575 [OR 1.62 (1.00–2.61)]. The cut-off level for TC ≥ 170 mg/dL was associated with rs2074192 OR 1.54 (1.04–2.28) and rs2158083 [OR 1.53 (1.04–2.25)]. Additionally, the haplotype (C-G-C) derived from rs879922-rs2158083-rs233575 was related to higher prevalence of overweight/obesity and TG elevation.

Conclusion

The expression and activity of ACE2 may be essential for CV homeostasis. Interestingly, the ACE2-SNPs rs879922, rs233575, rs2158083 and rs2074192, and the haplotype (C-G-C) of the three former could induce vulnerability to obesity and hyperlipidemia in women. Thus, these SNPs might be used as predictive biomarkers for CV diseases and as molecular targets for CV therapy.

Upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in vascular smooth muscle cells in angiotensin II-induced hypertension

Angiotensin II–induced vascular smooth muscle cell (VSMC) remodeling and dysfunction is a major contributor to the development of hypertension. In spite of the low content of mitochondria and their low contribution to bioenergetics in VSMCs, recent studies have suggested that mitochondria play an important role in the regulation of VSMC function. However, the role of mitochondria in angiotensin II–induced VSMC dysfunction remains unknown. Here, we found that angiotensin II decreased the expression of Bcl-2-like protein 1 (Bcl-xL), a newly identified protein in inhibition of uncoupled proton flux in mitochondria through interaction with the β-subunit of ATP synthase, and uncoupled mitochondria in VSMCs both in vivo and in vitro. Overexpression of Bcl-xL restored the mitochondrial and VSMC function in response to angiotensin II treatment in vitro, suggesting that angiotensin II uncouples mitochondria through downregulation of Bcl-xL. Mechanistically, angiotensin II increased the expression of miR-140-5p, which targeted and downregulated Bcl-xL in VSMCs. Inhibition of miR-140-5p using antagomir-140-5p in vivo attenuated mitochondrial uncoupling and hypertension in angiotensin II-treated mice. These results suggested that upregulation of miR-140-5p uncouples mitochondria by targeting Bcl-xL in VSMCs in angiotensin II–induced hypertension, and miR-140-5p and Bcl-xL are potential targets for treatment of vascular dysfunction.

The Effects of Angiotensin II or Angiotensin 1-7 on Rat Pial Microcirculation during Hypoperfusion and Reperfusion Injury: Role of Redox Stress

Renin-angiotensin systems produce angiotensin II (Ang II) and angiotensin 1-7 (Ang 1-7), which are able to induce opposite effects on circulation. This study in vivo assessed the effects induced by Ang II or Ang 1-7 on rat pial microcirculation during hypoperfusion-reperfusion, clarifying the mechanisms causing the imbalance between Ang II and Ang 1-7. The fluorescence microscopy was used to quantify the microvascular parameters. Hypoperfusion and reperfusion caused vasoconstriction, disruption of blood-brain barrier, reduction of capillary perfusion and an increase in reactive oxygen species production. Rats treated with Ang II showed exacerbated microvascular damage with stronger vasoconstriction compared to hypoperfused rats, a further increase in leakage, higher decrease in capillary perfusion and marker oxidative stress. Candesartan cilexetil (specific Ang II type 1 receptor (AT₁R) antagonist) administration prior to Ang II prevented the effects induced by Ang II, blunting the hypoperfusion-reperfusion injury. Ang 1-7 or ACE2 activator administration, preserved the pial microcirculation from hypoperfusion-reperfusion damage. These effects of Ang 1-7 were blunted by a Mas (Mas oncogene-encoded protein) receptor antagonist, while Ang II type 2 receptor antagonists did not affect Ang 1-7-induced changes. In conclusion, Ang II and Ang 1-7 triggered different mechanisms through AT₁R or MAS receptors able to affect cerebral microvascular injury.

Renin-Angiotensin System in Pathogenesis of Atherosclerosis and Treatment of CVD

Atherosclerosis has complex pathogenesis, which involves at least three serious aspects: inflammation, lipid metabolism alterations, and endothelial injury. There are no effective treatment options, as well as preventive measures for atherosclerosis. However, this disease has various severe complications, the most severe of which is cardiovascular disease (CVD). It is important to note, that CVD is among the leading causes of death worldwide. The renin–angiotensin–aldosterone system (RAAS) is an important part of inflammatory response regulation. This system contributes to the recruitment of inflammatory cells to the injured site and stimulates the production of various cytokines, such as IL-6, TNF-a, and COX-2. There is also an association between RAAS and oxidative stress, which is also an important player in atherogenesis. Angiotensin-II induces plaque formation at early stages, and this is one of the most crucial impacts on atherogenesis from the RAAS. Importantly, while stimulating the production of ROS, Angiotensin-II at the same time decreases the generation of NO. The endothelium is known as a major contributor to vascular function. Oxidative stress is the main trigger of endothelial dysfunction, and, once again, links RAAS to the pathogenesis of atherosclerosis. All these implications of RAAS in atherogenesis lead to an explicable conclusion that elements of RAAS can be promising targets for atherosclerosis treatment. In this review, we also summarize the data on treatment approaches involving cytokine targeting in CVD, which can contribute to a better understanding of atherogenesis and even its prevention.

Pyk2/MCU Pathway as a New Target for Reversing Atherosclerosis

Objective: Multiple mechanisms including vascular endothelial cell damage have a critical role in the formation and development of atherosclerosis (AS), but the specific molecular mechanisms are not exactly clarified. This study aims to determine the possible roles of proline-rich tyrosine kinase 2 (Pyk2)/mitochondrial calcium uniporter (MCU) pathway in AS mouse model and H₂O₂-induced endothelial cell damage model and explore its possible mechanisms.

Approach and Results: The AS mouse model was established using apolipoprotein E-knockout (ApoE^–/–) mice that were fed with a high-fat diet. It was very interesting to find that Pyk2/MCU expression was significantly increased in the artery wall of atherosclerotic mice and human umbilical vein endothelial cells (HUVECs) attacked by hydrogen peroxide (H₂O₂). In addition, down-regulation of Pyk2 by short hairpin RNA (shRNA) protected HUVECs from H₂O₂ insult. Furthermore, treatment with rosuvastatin on AS mouse model and H₂O₂-induced HUVEC injury model showed a protective effect against AS by inhibiting the Pyk2/MCU pathway, which maintained calcium balance, prevented the mitochondrial damage and reactive oxygen species production, and eventually inhibited cell apoptosis.

Conclusion: Our results provide important insight into the initiation of the Pyk2/MCU pathway involved in AS-related endothelial cell damage, which may be a new promising target for atherosclerosis intervention.

Edible and Herbal Plants for the Prevention and Management of COVID-19

Background: The outbreak of the pandemic coronavirus disease 2019 (COVID-19) has now become a global pandemic spreading throughout the world. Unfortunately, due to the high infectiousness of the novel β-coronavirus, it is very likely to become an ordinary epidemic. The development of dietary supplements and functional foods might provide a strategy for the prevention and management of COVID-19.

Scope and Approach: A great diversity of potential edible and medicinal plants and/or natural compounds showed potential benefits in managing SARS, which may also combat COVID-19. Moreover, many plants and compounds have currently been proposed to be protective against COVID-19. This information is based on data-driven approaches and computational chemical biology techniques. In this study, we review promising candidates of edible and medicinal plants for the prevention and management of COVID-19. We primarily focus on analyzing their underlying mechanisms. We aim to identify dietary supplements and functional foods that assist in managing this epidemic.

Key findings and Conclusion: We infer that acetoside, glyasperin, isorhamnetin, and several flavonoid compounds may prevent and/or be effective in managing COVID-19 by targeting the viral infection, reducing the host cytokine storm, regulating the immune response, and providing organ protection. These bioactive dietary components (used either alone or in combination) might assist in the development of dietary supplements or functional foods for managing COVID-19.

Isolation of Murine Primary Aortic Smooth Muscle Cells

Vascular smooth muscle cells (VSMCs) have been cultured for decades to study the role of these cells in cardiovascular disorders. The most common source of VSMCs is the rat aorta. Here we show the adaptation of this method to isolate and culture mouse aortic VSMCs. The advantage of this method is that there are many more transgenic mouse lines available compared to rats. The protocol consists of the isolation of the aorta, the liberation of vascular cells by the action of collagenase, culturing of VSCMs, and analyzing filamentous actin and alpha smooth muscle actin by fluorescence microscopy. VSCMs can be further used to study mechanisms underlying cardiovascular diseases. Graphic abstract: Figure 1.Working steps.